And more importantly is it possible to import data from GnuCash? Last time I tried it I failed.
The reason I was drawn to FF III in the first place was because of its aesthetic appeal and visualization features. The graphing and reporting abilities of GnuCash are not to my taste.
After some time, I settled down to converting from Gnucash to Ledger using PieCash (https://github.com/sdementen/piecash), and visualizing the ledger file using LedgerWeb (https://vifon.github.io/ledger-web/). A bit of a workaround, but can be scripted and works fine for me.
So it'll see a comma when I open the file on windows and just report an error.
Right now I'm considering running it in on my server and then connecting to it somehow from all the different platforms.
See the part about adding an environment file on Windows. On Linux, I set my LANG to en_US.UTF-8 but all the LC_* variables (apart from LC_ALL) to en_CA.UTF-8 and that gets me the right UI/formats mix in GnuCash (and also Chromium, which tries to speak British to me otherwise), and hopefully that works on Windows too.